Winterized turbocompressor unit and method for winterizing the turbocompressor unit

ABSTRACT

A winterized turbocompressor unit has a turbocompressor and an oil supply installation for supplying the turbocompressor with a lubricating oil, the lubricating oil being a low-temperature oil and the turbocompressor and the oil supply installation being set up to be operated with the low-temperature oil.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefits of European application No.07012385.6 filed Jun. 25, 2007, both of the applications areincorporated by reference herein in their entirety.

FIELD OF INVENTION

The invention relates to a winterized turbocompressor unit and a methodfor winterizing the turbocompressor unit.

BACKGROUND OF THE INVENTION

A turbocompressor is used in a chemical plant of the chemical industry.The chemical plant is established at a special location which may bedetermined, for example, by the presence of mineral resources. Themineral resources are, for example, natural gas which is extracted in aclimatic zone characterized by low temperatures, such as, for example, atundra. In the tundra, during the summer months, temperatures prevailwhich are just above freezing point, and in the winter months there aretemperatures which are well below freezing point. The turbocompressormust therefore be equipped so as to be adapted in such a way that it canbe operated reliably, free of faults, at the low temperatures,particularly during the winter months.

FIG. 2 shows a conventional turbocompressor unit 101. Theturbocompressor unit 101 has a turbocompressor 102 which has a rotor103. The rotor 103 is mounted by means of bearings 104, for example bymeans of tilting-segment plain bearings. The tilting-segment plainbearings 104 are customarily oil-lubricated. To supply thetilting-segment plain bearings 104 with a lubricating oil 113, theturbocompressor 101 has an oil supply installation 107 with an oilsupply line 108 and with an oil return line 109. The oil supply line 108is connected to one collective oil supply line 105 of theturbocompressor 102, via which line the lubricating oil 113 is suppliedto the tilting-segment plain bearings 104. To discharge the lubricatingoil 113 from the tilting-segment plain bearings 104, the turbocompressor102 has a collective oil return line 106 which is connected to the oilreturn line 109. Furthermore, the oil supply installation 107 has an oiltank 110 which is filled with the lubricating oil 113. To fill the oiltank 110, a filler neck 111 is provided on the oil tank 110. Built intothe oil tank 110 is an oil pump 112, by means of which the lubricatingoil 113 is conveyed to the tilting-segment plain bearings 104 by the oilsupply line 108 and the collective oil supply line 105.

The turbocompressor unit 101 is conventionally accommodated in the open,and therefore the turbocompressor unit 101 is exposed to the outsidetemperatures at its location. If the turbocompressor unit 101 isestablished in a tundra, the outside temperatures are at leasttemporarily so low that the lubricating oil 113 cannot be used foroperating the turbocompressor 102, that is to say for lubricating thetilting-segment plain bearings 104. The turbocompressor unit 101 istherefore provided with devices which make it possible that theturbocompressor unit 101 can be operated even at the low outsidetemperatures. These devices are a thermal insulation 114 (illustrateddiagrammatically in FIG. 2), by means of which the oil supply line 108is thermally insulated. Furthermore, the oil tank 110 has an oil heating115, by means of which the lubricating oil 113 in the tank 110 is heatedto a necessary operating temperature. The oil heating 115 isconventionally operated by means of electrical current.

The provision of the thermal insulation 114 and of the oil heating 115complicates the production of the turbocompressor unit 101 and iscost-intensive. If the oil heating 115 fails at low outsidetemperatures, the lubricating oil 113 in the oil tank 110 can no longerbe brought to the necessary operating temperature, and therefore theturbocompressor unit 101 has to be shut down. This could be remedied bycorresponding safety-relevant devices in order to make the oil heating115 fail-safe. These devices require an increased outlay in terms ofengineering in the planning and construction of the chemical plant, andalso increased investment expenditure.

SUMMARY OF INVENTION

The object of the invention is to provide a winterized turbocompressorunit and a method for winterizing the turbocompressor unit which can beoperated reliably at low outside temperatures, the outlay in terms ofengineering and the investment costs being low.

The winterized turbocompressor unit according to the invention has aturbocompressor and an oil supply installation for supplying theturbocompressor with a lubricating oil, the lubricating oil being alow-temperature oil and the turbocompressor and the oil supplyinstallation being set up to be operated with the low-temperature oil.

According to the invention, the low-temperature oil in theturbocompressor unit, with the turbocompressor and the oil supplyinstallation for supplying the turbocompressor with the low-temperatureoil, is used as the lubricating oil, the turbocompressor and the oilsupply installation being set up to be operated with the low-temperatureoil.

The method according to the invention for winterizing theturbocompressor unit, with the turbocompressor and the oil supplyinstallation for supplying the turbocompressor with the lubricating oil,has the step: introducing the low-temperature oil into the oil supplyinstallation as the lubricating oil.

The lubricating oil is the type of low-temperature oil, the minimumpossible operating temperature of which is lower than that of aconventional lubricating oil. The low-temperature oil can therefore beused at lower temperatures in order to operate the turbocompressor unitthan would be possible with the conventional lubricating oil. Such lowtemperatures are, for example, the outside temperatures in a coldclimatic zone, for example a tundra, during the winter months. Theturbocompressor unit does not need to be equipped with measures forwarming the lubricating oil and/or for keeping it warm, such as, forexample, oil heating which could keep the lubricating oil attemperature, and/or a thermal insulation of oil lines. This results in alow outlay in terms of the engineering of the turbocompressor unit andin low investment costs. Furthermore, when the turbocompressor unit isbeing operated, there is no need to consider too low a temperature ofthe lubricating oil, and therefore the turbocompressor unit is simple tooperate.

Preferably, the low-temperature oil is an oil according to ISO VG 46 andhas a low pour point at −54° C. and a capability as lubricating oil upto 20° C.

The turbocompressor unit which is operated with the low-temperature oilcan therefore advantageously be operated reliably down to an outsidetemperature of −20° C., without additional measures, such as, forexample, a thermal insulation of oil lines and/or oil heating, needingto be provided.

Furthermore, the low-temperature oil is an oil according to ISO VG 46and has a low pour point below −54° C. and a capability as lubricatingoil down to −30° C.

The turbocompressor unit can thus be operated with the lubricating oilat an outside temperature down to −30° C., without additional measures,such as, for example, a thermal insulation of oil lines and/or oilheating, needing to be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described below by means of a preferred exemplaryembodiment of the turbocompressor unit, with reference to thediagrammatic drawings in which:

FIG. 1 shows an exemplary embodiment of the turbocompressor unitaccording to the invention, and

FIG. 2 shows a conventional turbocompressor unit.

DETAILED DESCRIPTION OF INVENTION

As is clear from FIG. 1, a turbocompressor unit 1 has a turbocompressor2 which has a rotor 3 for the compression of gas. The rotor 3 is mountedby means of bearings 4. The bearings 4 are tilting-segment plainbearings which are supplied with lubricating oil 13 for theirlubrication. The lubricating oil supply is implemented by a supply ofthe lubricating oil 13 through a collective oil supply line 5 and adischarge of the lubricating oil through a collective oil return line 6.

Furthermore, the turbocompressor unit 1 has, for supplying the bearings4 with the lubricating oil 13, an oil supply installation 7 with an oilsupply line 8 and with an oil return line 9. The oil supply line 8 isconnected to the collective oil supply line 5 so as to conductlubricating oil, and the oil return line 9 is connected to thecollective oil return line 6 so as to conduct lubricating oil. The oilsupply installation 7 has an oil tank 10 to which both the oil supplyline 8 and the oil return line 9 are connected. The oil tank 10 has afilling with the lubricating oil 13 and a filler neck 11 by means ofwhich the lubricating oil 13 has been introduced into the oil tank 10.Furthermore, the oil tank 10 has an oil pump 12 which is built into theoil tank 10 in order to convey the lubricating oil 13 into the oilsupply line 8.

By the oil pump 12 being operated, the lubricating oil 13 is sucked outof the oil tank 10 and conveyed into the oil supply line 8. Thelubricating oil 13 is conveyed from the oil supply line 8 into thecollective oil supply line 6 and is delivered to the bearings 4 fortheir lubrication. The lubricating oil 13 runs from the bearings 4 intothe collective oil return line 6 and into the oil return line 9 in orderthen to pass back into the oil tank 10. An oil circuit is thus formed bythe oil pump 13, the oil supply line 8, the collective oil supply line5, the collective oil return line 6, the oil return line 9 and the oiltank 10.

The lubricating oil 13 is a low-temperature oil, for example the oil“Shell Corena AS, ISO VG 46”.

In the turbocompressor unit 1, in particular, neither the oil supplyline 8 nor the oil return line 9 are provided, thermally insulated.Furthermore, oil heating is not provided in the oil tank 10.

When the lubricating oil 13 is circulated in the oil circuit, it has acertain dwell time in the oil tank 10 on account of its volume. As arule, the dwell time is of a length such that the lubricating oil 13 inthe oil tank 10 assumes the ambient temperature of the latter. When thelubricating oil 13 passes through the bearings 4, the lubricating oil 13in the bearings 4 is warmed on account of frictional effects in thebearings 4. The lubricating oil 13 thus warmed is then returned by thecollective oil return line 6 and the oil return line 9 into the oil tank10. There, the warmed lubricating oil 13 cools again to the ambienttemperature of the oil tank 10.

Since the lubricating oil 13 has a low pour point at −54° C., theturbocompressor 2 can be operated reliably, and free of damage, down toan ambient temperature of the turbocompressor unit 1 of −20° C. Theturbocompressor unit 1 can therefore be operated reliably in a climaticzone in which the ambient temperature does not fall below −20° C.

1.-9. (canceled)
 10. A winterized turbocompressor unit, comprising: aturbocompressor; and an oil supply installation that supplies theturbocompressor with a lubricating oil wherein the lubricating oil is alow-temperature oil and the turbocompressor and the oil supplyinstallation are configured and arranged to operate with thelow-temperature oil.
 11. The turbocompressor unit as claimed in claim10, wherein the low-temperature oil is an oil according to ISO VG 46 andhas a low pour point at −54° C. and operates as the lubricating oil downto −20° C.
 12. The turbocompressor unit as claimed in claim 10, whereinthe low-temperature oil is an oil according to ISO VG 46 and has a lowpour point below −54° C. and operates as the lubricating oil down to−30° C.
 13. A method of operating a turbocompressor unit with alow-temperature oil, comprising: providing a turbocompressor; arrangingan oil supply installation for supplying the turbocompressor with thelow-temperature oil as a lubricating oil wherein the turbocompressor andthe oil supply installation are configured and arranged to operate withthe low-temperature oil.
 14. The method as claimed in claim 13, whereinthe low-temperature oil is an oil according to ISO VG 46 and having alow pour point at −54° C. and operates as the lubricating oil down to−20° C.
 15. The method as claimed in claim 13, wherein thelow-temperature oil is an oil according to ISO VG 46 and having a lowpour point below −54° C. and operates as the lubricating oil down to−30° C.
 16. A method for winterizing a turbocompressor unit, comprising:providing a turbocompressor with an oil supply installation thatsupplies the turbocompressor with a lubricating oil; and introducing alow-temperature oil into the oil supply installation as the lubricatingoil.
 17. The method as claimed in claim 16, wherein the low-temperatureoil is an oil according to ISO VG 46 and has a low pour point at −54° C.and operates as the lubricating oil down to −20° C.
 18. The method asclaimed in claim 16, wherein the low-temperature oil is an oil accordingto ISO VG 46 and has a low pour point below −54° C. and operates as thelubricating oil (13) down to −30° C.